As is true with most companies, utility companies are striving to reduce overhead costs, while providing more convenience to customers. For example, electric companies are migrating from costly and time-consuming manual methods of determining the amount of power consumed by customers of the power company. Traditionally, a person periodically came to the customer's home, and requested entry to read the consumer power usage from a power meter. This type of process was costly, slow, and intrusive to their customers. In order to alleviate some of the problems associated with the traditional approach, other approaches have been employed, including wireless and modem transmission of power usage amount.
However, it is often the case that there is information that the power company may want to provide to their customers. While general information, such as the current price of power, price increases, etc. may be made available to customers via mail or telephone, it is again costly, time consuming, and intrusive.
Furthermore, many power companies provide customers with cost discounts if the customer agrees to allow the power company to temporarily adjust or terminate their power consumption for certain "non-essential" power-consuming devices (e.g., air conditioners, water heaters, swimming pool heaters, etc.) during peak operation. This is commonly referred to as "load control" or "load limiting". This allows the power company to limit the peak power consumption when necessary. Otherwise, the power company may have to purchase more expensive power from alternative sources to meet its peak load demand. A one-way wireless pager technology could be used to service the peak load in this manner. For example, a power company could send a digital message via one-way pager technology to a particular geographic area including a number of customers who have agreed to allow the power company to alter their power during peak power periods. The pager at the destination would receive a digital word indicating that the power should be temporarily terminated. Because the communication would be unilateral, no signal acknowledge would be provided, and there would be no manner, short of a trial-and-error method, to determine whether the customer's power to these appliances was ever suspended. Furthermore, customers could also tamper with the pager systems to avoid having their power temporarily terminated, while continuing to obtain the cost discount.
Therefore, it would be desirable to allow information to be provided from the power company to any one or more of their power consumers, while allowing for receipt acknowledgment and other signals. It would also be desirable to utilize power distribution line to provide such information, in order to avoid new wiring and its associated costs and installation time requirements. Utilizing the existing power distribution line would also minimize customer tampering during load control periods, as tampering with or severing the control line would be tantamount to eliminating their own source of power because the power is transmitted on the same conductor. The use of frequencies having a very long wavelength would also be desirable, to minimize the need for signal repeaters, and to minimize harmonic effects and reduce the overall noise on the power line which can adversely affect electronic devices such as computers.
While the prior art does not provide the aforementioned functionality, the present invention provides a solution to these and other shortcomings of the prior art, and further provides additional advantages over the prior art.